LCABIE, IPREM, Université de Pau et des Pays de l'Adour/CNRS UMR 5254, Hélioparc, 2 Avenue du Président Pierre Angot, Pau, 64053, France.
Anal Chem. 2010 Jul 1;82(13):5652-62. doi: 10.1021/ac100648f.
A new approach was demonstrated for the isotope ratio measurement in different elemental species of Hg using transient signal obtained by chromatography coupled with multicollector-inductively coupled plasma mass spectrometry (MC-ICPMS). The method based on the slope of linear regression by transient intensities of different isotopes shows improved accuracy and reproducibility (0.2-0.5 per thousand as 2 standard deviation (SD)). Internal precision (RSD) of the method is very close to the theoretical value given by the counting statistic and is better by a factor of 6 in comparison with previous conventional methods of calculation. We demonstrated that internal RSD (uncertainty) depends on regression coefficients of the linear function (R(2)). The typical internal precision of isotopic ratio measurements (0.003-0.02%) was achieved for delta(202)Hg when injecting as low as 90 pg of Hg species. With the new methodology, it is possible to (i) measure the isotopic composition when a sample and a bracketing standard have significantly different concentrations, (ii) measure the isotopic composition of different species in samples versus single species in a bracketing standard, and (iii) measure the isotopic ratios for low abundant isotopes. We demonstrated application of this method for different environmental samples and processes.
一种新的方法被证明是用于测量不同元素物种中的汞同位素比值，使用色谱与多接收电感耦合等离子体质谱（MC-ICPMS）联用得到的瞬态信号。该方法基于不同同位素瞬态强度的线性回归斜率，具有提高的准确性和重现性（0.2-0.5 千分比，作为 2 个标准差（SD））。该方法的内部精度（RSD）非常接近计数统计给出的理论值，并且比以前的常规计算方法要好 6 倍。我们证明了内部 RSD（不确定性）取决于线性函数的回归系数（R²）。当注入低至 90 pg 的汞物种时，δ（202）Hg 的同位素比值测量的典型内部精度为 0.003-0.02%。使用新方法，可以（i）测量当样品和内标具有显著不同浓度时的同位素组成，（ii）测量样品中不同物种的同位素组成与内标中单个物种的同位素组成，以及（iii）测量低丰度同位素的同位素比值。我们展示了该方法在不同环境样品和过程中的应用。
